The major aim of this Core is to provide an imaging analysis facility for the investigators of this Program Project. The Core assists in experiments that require expertise and specialized equipment not available in the individual subproject laboratories. The members of the Core II will provide guidance and expert help to the different members of the PMI in the various imaging methods that are available in the Core II and in the associated microscopic facilities being developed through the various Shared Instrument grants. Core II also serves to train postdoctoral and predoctoral fellows of PMI members in the use of microscopes. This training role of the Core II will continue to be a high priority. The Core now and for the duration of the proposed grant period will be focusing on quantitative analysis of fluorescent probes inside living cells. The approaches include videomicroscopy, 3-D reconstruction of confocal images, cell motility assays, fluorescence polarization, photoactivation of caged compounds, low light level detection methods, and immunofluorescence. Core II also possesses the equipment for microinjecting, into living cells, unlabeled and labeled proteins as well as plasmids containing cDNAs for different cytoskeletal proteins.